Empty and load apparatus



E. E. HEwn-T 2,155,225'

EMPTY AND LOAD APPARATUS April 1s, 1939.

5 Sheets-Shee-t l Filed April ll, 1936 lowA f .5520 l mvEN-roR ELLIS E HEWITT ATTORN EY April 1s, 1939. E E. HEwm l 2,155,225

EMPTY AND LOAD APPARATUS Filed April 11, 1956 5 Sheets-Sheet 2 I l@ sq -f 7 3 e l @e ATTORNEY April 18, 1939.

E. E. HEwlTT EMPTY AND LOAD APPARATUS Filed April 11I 193e 3 Sheets-Sheet 3 INVENTOR ELLIS E. HEWITT ATTORNEY' Patented Apr. 18, 1939 omiten STATES PATENT orties f 14 Cairns. (01; 30a-1) l This invention relates to empty and load brake equipment for vehicles, and more particularly to that type of equipment which is adapted to be automatically set or conditioned for either light or heavy load braking according to the position the vehicle body assumes relative to a fixedvpart of a truck of the vehicle under light and heavy loads. I

'Ihe mechanism for conditioning the brake equipment is usually carried by the vehicle body and is movable vertically therewith and is adapted to be controlled according to the position which the body assumes relative to a xed part of the vehicle truck under light and heavy loads. This fixed part of the truck, as heretofore proposed, has been in the form of a vertically disposed strut which, at its lower end, is supported either directly by the spring plank of the truck or by any other suitable member of the truck which is incapable of vertical movement relative to the side frame. The upper end of the strut is adapted to cooperate with a control cylinder device of the change-cver mechanism to control the operation of the mechanism for either light or heavy load service.

There is an increasing interest being shown toward the reduction in the dead weight of railway cars and toward making the trucks of such cars more flexible under ordinary service conditions, and in order to do this it has been proposed to eliminate the truck spring plank which has considerable weight. When the spring plank is omitted from the truck, it isressential vthat some other support be provided for the changeover control strut and to meet this need it has heretofore been proposed to provide a very light strut support which extends transversely of the truck and which is supported at its ends by the parallel side frames of the truck but which does not serve to tie the side frames together.

When the control cylinder device is carried by the body ci the vehicle it is oi course very desirable to have the device and the strut for controlling its operation position-ed as near as is practicable to the pivotal connection between the vehicle body and truck Where Variations in the distance between the control cylinder device and ihe strut, when the body tilts relative to the strut, is so slight as not to interfere with or in any way change the control of the control cylinder device.

The principal object of the present invention is to provide an improved empty and load iiuid pressure brake change-over control means which is carried by a truck of a vehicle and which is located at the-outer side of one oi the truck side frames'where it is easily accessible for adjustment, inspection and repair.

Another object of the inventionis to provide an improved control means for an empty and load brake change-over apparatus which does not require a control strut supported by a truck spring plank or any other transversely extending strut supporting truck member, thus simplifying the change-over control means and truck construction.

A further object of the invention is to pro-- vide an improved control cylinder means for an empty and load fluid pressure brake changeover` mechanism and improved means for adjusting the control cylinder means to automatically function to elect the desired operation of the change-over mechanism for either light or heavy braking,

Other objects and advantages will appear in the Afollowing more detailed description ofthe invention.

As-,shown inthe accompanying drawings, Fig. 1 is' a fragmentary cross-sectional View of a railway vehicle embodying the invention, the View being taken just ahead of the pivotal connectionl between the vehicle body and a supporting truck therefor; Fig. 2 is a fragmentary plan View l of a portion of the truck showing the empty and load change-over control means mounted thereon, the vehicle body being omitted to more clearly illustrate the invention; Fig. 3 is a side elevational View of a portion of a side frame of the truck and the control means vmounted thereon; Fig. 4 is a detail Vertical section View drawn on a large scale of the control means; Figs. 5 and 6 are fragmentary sectional views taken'on the lines 5;5 and B-S respectively of Fig. 4; Fig. '7 is a detail view, mainly in section, of one of the hose couplings carried by the truck bolster and by the body bolster of the vehicle and Fig. 8 is a diagrammatic view partly in section of an empty and load fluid pressure brake equipment adapted to be controlled by the improved control means.

As shown in the drawings, the railway vehicle comprises a body l and the usual supporting trucks 2, only a portion of one of the trucks and a portion of the body being shown.

The car truck may comprise the usual spaced side frames 3 which are carried by truck Wheels i through the medium of the usual axles, axle bearings and journal boxes A(not shown), and may also comprise a truck bolster 5 which is carriedrbythe truck frames 3 through the mevopening 8 by the adjacent side frame.

dium of the usual springs 6 which are carried `by the bottom members or chords of the side bolster, as shown, is of hollow form-and is made n of cast metal and, intermediate its ends, is provided with an integral center plate 9 which is adapted to cooperate with the uasual body center plate I9, carried by the body bolster of the car bodyV I, to form the pivotal connection between the truck and car body.

Secured to one end of the truck bolster 5 is a header IZ having fluid conducting passages I3 and I4 which are connected through pipes I5 and I 6, respectively, to uid conducting passages and I8, respectively, in a header-I9 secured to a vertically disposed side wall of the truck bolster, said header |9 being located adjacent the truck center plate 9. 'I'he passages I1 and |8 of the header |9 are respectively connected through flexible-hose connections 2l] and 2| to passages 22 and 23, respectively, of a bracket 24, which bracket, in the present embodiment of the invention, is secured to the body bolster Il, at a point adjacent the body center plate IB.V The exible hose connections 20 and 2| are arranged adjacent the pivotal connection between the body and truck of the vehicle where horizontal pivotal movement between the body and truck bolster as well as the sidewise sway of the body bolster relative to the truck bolster is not so great, thus making it would otherwise be the case. By thus keeping the exible connections short they are not 'so liable to become kinked as longer connections when the .truck and body bolster are in their normal positions, that is to say,l when the bolsters are in vertical alignment with each other as when the vehicle is on a straight stretch of track.

The iiuid pressure brake equipment and the change-over valve mechanism associated therewith, as shown in Fig. .8, may be the same as that shown, described and claimed in a pending joint application of Earle S. Cook and myself, Serial No. 51,798, led November 27, 1935. In view of this the brake equipment and change-over mechanism are briefly described as comprising the usual brake pipe 84, a brake controlling valve device 25, an auxiliary reservoir 2G, an emergency reservoir 21, an empty brake cylinder 28 and a load brake cylinder 29, a transfer valve device 3| and a change-overvalve device 32'. Y

Since the several parts of the vchange-over valve. mechanism have been fully described in the aboveY mentioned pending application only one portion thereof, namely, the change-over control valve device 33, will be described in more or less detail.

The change-over control valve device 33 may comprise a casing in which there is mounted a flem'ble diaphragm 34, at one side of which diaphragm is a chamber 35 which is constantly connected through a passage 31 with the atmosphere and at the opposite side of which there is a valve chamber 3B containing a slide valve 39 which is adapted to be operated by a stem 40 operatively secured to the flexible diaphragm. Contained in the chamber 35 is'a spring 4| which, at all times, .tends to urge the diaphragm,

stem and slide valve downwardly. The brake pipe 84 is connected through a branch pipe42, a combined cutout cock and dirt collector de- Vice 43, a ller piece 44 which is clamped between the casings of the brake controlling valve ydevice 25 and cut-out cock and dirt collector 43 and a pipe and passage 45.

Leading from the seat for the slide valve 39 of the valve device 33 to the passage 22 of the bracket 24 is a passage and pipe 35, and leading from the change-over valve device 25 to the passage 23 of the bracket 24 is a pipe 35.

For the purpose of controlling the operation of the change-over control mechanism a control cylinder device 45 is provided which instead of being carried by the vehicle body as is the control cylinder device in the apparatus disclosed in the aforementioned pending application, is'

preferably carried by the header I2 secured to V'one end of the truck bolster.

register with the passages VI3 and I4, respective-V ly, of the header I2 when the flange is clamped to the header.

Mounted in the cylinder casing for reciprocatory movement relative thereto is a control piston 52' having a piston rod 53 which extends through and is slidablyV guided in the non-pressure head 54 of the cylinder casing. Contained in a recess formed by an annular flange 55 which projects outwardly from the non-pressure head 54 is a sealing mechanism 58 which surrounds and engages the piston rod to prevent moisture and dirt from entering the cylinder by way of the usual clearance space which is provided between the piston rod and the non-pressure head.

At one side of the control piston 52 is a chamber 51 which is connected to the passage 59 and at the other side of the piston is a nonpressure chamber 58 which is constantly connected to the atmosphere through a downwardly directed breather passage 59 containing straining material 6U which is maintained in place by means of a plug 6| which has screw threaded connection with the casing, said plug having a plurality of narrow slots 52 formed therein providing communication between the passage 59 and the atmosphere. With the piston in its uppermost or normal position, the passage 5| is connected to the non-pressure chamber 58.

Contained in the chamber 58 isa coil spring 83 which is interposed between and operatively engages the control piston 52 and the nonpressure head of the cylinder and which tends, at all times, to urge the piston toward its uppermost or normal position. Y

The outer end portion 64 of the piston rod is provided with an extension or shoe 55 comprising a sleeve portion 55 which has screw threaded connection with the piston rod to render the extension adjustable relative tothe piston rod. To prevent accidental relative rotation between the piston rod and extension 55 there is removably mounted in the piston rod a cotter pin 61 which is adapted to engage the sleeve portion within slots 68 through `which the cotter pin is easily accessible for removal from the piston rod and sleeve portion.

The lower end of the extension B is adapted to engage with the stop lug 69 of a bracket 18 riveted or otherwise secured to the truck bolster column guide member of the side frame of the truck.

The piston rod, intermediate its ends is provided with a tell-tale means which in the present embodiment of the invention is in the form of a hole 1l of small diameter which when the piston is in its outermost position is adapted to be seen through either one of two notches v12 provided in the annular flange 55 which projects outwardly from the non-pressure head of the cylinder. When the hole can be seen through either notch 12, the one whose duty it is to maintain the brake mechanism properly adjusted, will know that the piston is in its innermost posi'- tion, thus facilitating the adjustment of the control apparatus, as will hereinafter more fully appear.

The breather passage 59 in the cylinder casing is of larger diameter at its outer or atmospheric end than at its inner end and due to the differences in diameter an annular shoulder 13 is formed in the passage. The straining material Sli in the present embodiment of the invention comprises a piece of felt or other material pervious to air which is made square in cross section and which when forced in place bythe plug BI engages the annular shoulder 13 and completely bridges the portion of the passage 59 which is of the smallest diameter, so that no air can enter the chamber 58 of the cylinder casing without first passing through and being cleansed of moisture and dirt by the strainingmaterial 65.

The inner end of the plug 5l is also provided with a plurality of spaced radially arranged grooves 15 through which fluid admitted through the slots 52 is adapted to pass to the space between each of the four sides of the straining material 55 and the adjacent wall of the passage 59 without having to pass through the straining material. It will be appreciated that some of the fluid entering the slots 52 of the plug 'l directly enters the outer end of the straining material and some passes through the grooves 14 and enters the straining material at each of its four sides. Since fluid is free to pass through the straining material from five of its sides the possibilities of the straining material being clogged by dirt or moisture extracted from thev fluid are reduced to a minimum.

The ends of the flexible hose 2i) and 2l are connected to the header I9 and bracket 24 by means of hose ttings 15, each of which fittings is secured to the respectivey header or bracket by means of bolts or any other suitable securing medium. Each fitting 15 is provided with a hollow extension l5 over which the adjacent end. of the hose is adapted to nt, the extension being provided with an enlarged spherical portion 1l' to ensure an airtight iit between the hose and the fitting. Ticlack of the portion 11 the hose is secured to tho extension 15 by means of a hose clamp 18.

In most instances the control mechanism for the change-over apparatus will be so adjusted as to assume load position when the Vehicle is loaded to slightly more than half of its capacity and such adjustment is preferably made when the empty, the adjustment is made as follows; the piston rod 55 is moved downwardly manually until the hole 'll is visible through the notches 12. lf when the hole is sighted, the extension 65 is in engagement with the lug 59 no adjustment of the extension relative to the piston rod is necessary, but if the extension is not in such engagement when the hole is sighted, the cotter pin G1 is removed and then the extension is rotated toward the left hand until such time as it engages the lug. If when the extension 65 is in engagement with the lug S9, the hole 1I is not in view, the extension is rotated toward the right. relative to the piston rod until the hole is in view. When the extension has been adjusted. to its proper position as just described, the cotter pin 5l is again secured to the piston rod so as to lock the extension against accidental rotation relative to the piston rod thereby maintaining the extension in its adjusted position.

If at any time it should happen that when the bracket 'l5 is secured to the side frame in the manner shown in Fig. 3 the extension cannot be adjusted to engage the lug 59, the rivets which secure t. e bracket to the truck side frame must be removed and the bracket raised so that the holes 19, with which the bracket is provided, register with the corresponding holes in the frame. When the bracket is thus raised it is again riveted in position.

Operatie/n. of the control meansy om, an empty car Normally the spring 63 of the control cylinder device maintains the piston 52, piston rod 53 and piston rod extension 65 in their uppermost position in which the extension is out of engagement with the lug 65 as shown in Figs. 1 and 3 so as to prevent the usual vertical movements of the truck bolster relative to the truck side frame due to service shocks in transit, from being transmitted to theV control vcylinder device.

According to the invention the control cylinder device 45 functions to control the operation of the change-over valve mechanism for either empty or load service when the equipment. is being initially charged with fluid under pressure as will hereinafter more fully appear in the description of the operation of the brake equipment.

Assuming the brake equipment to be at atmos pheric pressure, the slide valve 39 of the changeover control valve device will not be in `the position in which it is shown in Fig. 8 but will be in its innermost or lower position in which the passage 35 is connected to the slide valve chamber 5:25, said valve being yieldably maintained in this position by the spring Ill acting through the medium of the diaphragm 34 and iaphragm stem 50. With the slide valve in this position the passage l5 which is connected to the brake pipe Si', remains connected to the valve chamber 38.

In initially charging the brake equipment iiuid under pressure supplied to the brake pipe 84 in the usual manner flows through the branch pipe combined cut-out cock and dirt collector device 133. and filler piece lll! to the several chambers ci the brake controlling valve device which are to becharged and to the auxiliary and emergency reservoirs 25 and 21, respectively, in the usual manner.

'I luid under pressure not only ows through the filler piece fill to the brake controlling valve device but also flows to the valve chamber 38 of vehicle'is empty. Assuming the vehicle to be the control change-over valve device 33 by way of pipeY and passage 45. Since the slide valve 39 of the device 33 is in its innermost position, fluid under pressure flows from the valve chamber 38 to the piston chamber 51 of the control cylinder device 46 by way of passage and pipe 36, passage '22 in the bracket 24, hose 26, passage l1 in the header I9 carried by the truck bolster, pipe l5, passage i3 in the header l2 at the end of the bolster and passage 56 in the flange and casing of the cylinder control device.

When the pressure of fluid in piston chamber 51 has been increased to about thirteen pounds, the piston 52 and thereby the piston rod 53 and piston rod extension 65 will be caused to move downwardly againsty the opposing pressure of the spring 63. K

Since the car is empty, the piston 52 Will move far enough to connect the passage 5| to the piston chamber 51 and when this communication has been established the piston rod extension 65 is engaged by the lug 69 thus bringing the piston to a stop. Fluid under pressure now flows from chamber 51 to the change-over Valve device 32 by way of passage 5I, passage I4 in the header l2 at the end of the truck bolster, pipe i6,

said. diaphragm asit is thus flexed acting, through the mecium of the diaphragm stem 43,'to shift the slide valve 3S to the positionin which it is shown in Fig. 8, In this position a cavity 85 in the valve'connects passage 36 to a passage 8l which leads to the atmosphere. VSince the pisv ton chamber 51 is in communication with the passage 36 uid under pressure is vented from the pistonl chamber 51. When due to the flow of fluid from the piston chamber 51 to the atmosphere, the pressure of fluid in said chamber has reduced to slightly below the value of the spring 63 (thirteen pounds), said spring acts to move the control piston 52 and consequently the piston rcd 53 and piston rod extension 65 to their `uppermost position as shown in Figs. 1 and 3. The piston after it has moved a short distance toward its upper position first cuts olf the communication between the control piston chamber 51 and passage 5I which is in communication with the change-over valve device and then connects the passage 5l to the chamber 58, so that fluid under pressure is now vented from the change-over valve device.

Now when a reduction in brake pipe pressure is effected, the brake equipment will function in the same manner as described in the aforementioned pending application to supply fluid under pressure to the empty brake cylinder 28 to effect light braking of the car.

YOperation of the control means on a loaded car that when fluid under pressure is supplied to the control piston chamber 51 of the control cylinder device 56, the extension'65 will be engaged by the lug 69 and the piston 52 thereby brought to a stop before it canV uncover the passage 5IV to the chamber 51. The piston in this position will not close -communication from the passage 5l and consequently from the pipe 30 to the chamber 58 which is at atmospheric pressure.

When the pressure of fluid in passage 36 has been increased to about twenty pounds fluid under pressure is caused to flow from the passage 36 to the change-over valve device in the same manner as described in the aforementioned pending application. With the passage 5l and consequently the pipe 30 at atmospheric pressure, fluid under pressure flowing from the passage 35 to the change-over valve device causes the device to assume heavy or load braking position.

When the pressure. of fluid in slide valve chamber 38 of the control valve device 33 has been increased to around thirty pounds, the diaphragm 311i flexes and causes the slide valve 39 to be shifted to the position in which it is shown in Fig. 8, in which position the cavity 80 connects passage 36 to the passage Si leading to the atmosphere so that iiuid under pressure is vented from the piston chamber 51 of the cylinder control valve device. With the chamber 51 thus vented, the spring acts to move the control piston 52 and thereby the piston rod 53 and piston rod eXtensicn 65 totheir upper position in which the extension is out of contact with the stop lug 69.

New when a reduction in brake pipe pressure is effected, the brake equipment will function in the same manner as described in the aforementioned pending application to supply fluid under pressure to both the empty brake cylinder 28 and the load brake cylinder 29 to effect heavy braking of the car.

It will be understood that the operation of the change-over valve mechanism to condition the fluid pressure brake equipment for either light or heavy braking will be identical'with that of the corresponding mechanism disclosed in the aforementioned pending application and for this reason only those parts of the mechanism which are under the control of the control cylinderdevlce .y 50

or which exercise some control over the control cylinder device have been described in more or less detail.

It will also be understood that with the brake v equipment conditioned for either light or heavy braking the rrelease of the brakes will be accomplished in the same manner as described in said pending application. y

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that embodiment or otherwise than by the terms of the appended claims. Y

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. In a controlling mechanism for an automatically operative change-over apparatus of an empty and load fluid pressure brake equip-ment, in combination, a vehicle truck comprising a truck framea truck bolster movable vertically relative to said frame according to the load on the vehicle, a laterally extending lug rigidly connected to said frame and projecting outwardly from an outer vertically disposed face of the side frame, and means disposed above said lug and carried by said bolster operated by fluid under pressure for controlling the operation of said change-over apparatus, said lug being adapted to cooperate with said means -to control the operation of said means according to vertical movement of said bolster relative to said side frame and lug. y

2. In Van empty and load brake equipment for a vehicle, ncombination, a vehicle body, a truck comprising a truck frame and a truck bolster pivotally connected to and supporting said body, said truck bolster being movable vertically relative to said truck frame according to the load on the body, fluid pressure brakeapparatus carried by said body operative at one time to produce a light degree of braking and operative at another time to produce a heavy degree of braking, means carried by said truck and controlled according to the vertical movement of said truck bolster relative to said truck frame and by uid under pressure for conditioning the fluid pressure brake apparatus for either light or heavy braking, and iluid conducting control conduits connecting said iluid pressure brake apparatus and means, the portions of said conduits bridging the space between said body and truck being flexible to accommodate relative pivotal movement between said truck and body and the portions of said conduits extending from the flexible portions to said means being enclosed by said bolster.

' 3. In an empty and load Vbrake equipment for a vehicle, in combination, a vehicle body, a truck comprising a truck frame anda truck bolster pivotally connected to and supporting said body, said truck bolster being movable vertically relative to said truck frame according to the load on the body, iluid pressure brake apparatus carried by said body operative at one time to produce a light degree of braking and operative at another time to produce a heavy degree of braking, means carried by said truck bolster and controlled according to the vertical movement of said truck bolster relative to said truck frame and by fluid under pressure for conditioning the fluid pressure brake apparatus for either light or heavy braking, iluid conducting control pipes connected with said means and carried and enclosed by said truck bolster, corresponding fluid conducting control pipes connected with the fluid pressure brake apparatus, and exible conduits connecting the control pipes in the vicinity of the pivotal connection between said truck bolster and body.

4. In a vehicle empty and load iiuid pressure brake equipment adapted to l be automatically conditioned for either light or heavy braking, in combination, a vehicle on which the brake equipment is mounted, a truck comprising a side frame and a truck bolster pivotally connected to and supporting said body, said truck bolster being movable vertically relative to the side frame according to the load on the body, means carried by said truck and operative by fluid under pressure supplied from said fluid pressure brake equipment when the equipment is being charged and according to the vertical movement of said bolster relative to said side frame for eiecting the conditioning of the brake equipment for either light or heavy braking, and fluid conducting control conduits connecting said means and brake equipment, said conduits extending from said truck to said body adjacent the pivotal connection between said truck bolster and body.

5. In a vehicle empty and load fluid pressure brake equipment adapted to be automatically conditioned for either light or heavy braking, in combination, a vehicle on which the brake equipment is mounted, a truck comprising a side frame and a truck bolster pivotally connected to and supporting said body, said truck bolster being movable vertically relative to the side frame according to the load on the body, means carried by said truck and operative by fluid under pressure supplied from said iiuid pressure brake 4equipment when the equipment is being charged and according to the vertical movement of said bolster relative to said side frame for effecting the conditioning of the brake equipment for either light or heavy braking, and iluid conducting control conduits connecting saidmeans and brake equipment, said conduits extending laterally of the truck to a point adjacent the pivotal connection between said truck bolster and body and then upwardly across the space between said truck and body to the brake equipment.

6. In a vehicle empty and load fluid pressure brake equipment adapted to be automatically conditioned for either light or heavy braking, in combination, a vehicle on which the brake equipment is mounted, a truck comprising a side frame and a truck bolster pivotally connected to and supporting said body, said truck bolster being movable vertically relative to the side frame according to the load on the body, means carried by said truck bolster and operative by fluid under pressure supplied from said fluid pressure brake equipment when the equipment is being charged and according to the vertical movement of said bolster relative to said side frame for effecting the conditioning of the brake equipment for either light or heavy braking, and fluid conducting control conduits connecting said means and brake equipment, said conduits extending longitudinally through said bolster to a point adjacent the 'i and projecting outwardly therefrom, means carried by said bolster operated by fluid underrpressure for controlling the operation of said change* over apparatus, said lug being adapted to cooperate with said means to control the operation of said means according to vertical movement of said bolster relative to said side frame and lug, and means operative manually for adjusting said means relative to said lug to'ensure the desired control operation of said means.

8. In a controlling mechanism for an automatically operative change-over apparatus of an empty and load fluid pressure brake equipment,

in combinationy a vehicle truck having an element, a truck bolster movable vertically relative to said element according to the load on the vehicle, and means adapted toA cooperate with said bolster and element and operative accordf.

ing to the Vertical movement of said bolster relative to said element for controlling the operation of said change-over apparatus, said means comprising a movable control member having two control positions, a shoe having screw threaded Vvconnection with one end of said member, and a stop adapted to engage .said shoe to position said control member according to the vertical movement of the truck'bolster relative to said element, said stop being adapted to be secured to the truck in either one oi tWo positions vertically of thel truck and said shoe being adjustable relative to said member and element.

9. In a cylinder mechanism comprising a casing, a piston mounted to reciprocate in said casing, a pressure chamber at one side of said piston and a non-pressure chamber at the other side of the piston, a breather passage leading from the atmosphere to said non-pressure chamber, Va section of straining material in said breather passage compietely bridging 'a portion of. said passage and only partially bridging another portion of the passage to permit air entering the breather passage from the atmosphere to kenter the outerV end and sides of said section of straining material, and a plug having screw threaded connection with said casing for maintaining said `section oi straining material in the breather passage, said plug having openings through which air flows to the end oi said strainer and having grooves through which air owing to the end of Said section of straining Vvmaterial is permitted to flow to the sides of said section.

10. In a controlling mechanism for an automatically operative change-over apparatus of an empty and load fluid pressure brake equipf ment, in combination, a vehicle truck comprising a side frame having a truck bolster accommodating opening formed therein, a truck bolster movable vertically relative to said side frame according to the load on the vehicle and extending `11`, vIn a controlling mechanism'for an auto- Y matically operative change-over apparatus of an empty and load fluid pressure brake equipment, in combination, a vehicle truck comprising a side frame having artruck bolster accommodating openings formed therein, a truck bol- I ster movable vertically relative to said side frame i brake equipment adapted to be automatically conditioned for either light or heavy braking, in combination, a vehicle body on which the brake equipment is mounted, a truck comprising a side,

frame and a truck bolster pivotally supporting said body and being movable vertically relative to the side frame according to the load on the body, a header secured to one end of the bolster, means secured to said header operative by fluid under pressure supplied from said fluid pressure brake equipment when the equipment is being charged with uid under pressure and according to the vertical movement of said bolster relative to the side frame for conditioning the equipment for either light or heavy braking, and iluid pressure control communications` Y connecting said means and uid pressure brake equipment, said communications extending through said header and longitudinally through said bolster to a point adjacent the pivotal support for the vehicle body and from thence tothe fluid pressure brake equipment. Y Y

13. In a vehicle empty and load fluid pressure Vbrake equipment adapted to be automatically conditioned `for either light or heavy braking, in combination, a vehicle body on Which the brake equipment'is mounted, a truck comprising a side frame and a truck bolster pivotally supporting said body and being movable vertically relative to the side frame according to the load on the body, a header secured'to one end of the bolster, meansrdisposed at one sideofsaid bolster and secured to said header operativeby uid under pressure supplied from said fluid pressure brake equipment when the equipment is being charged with iiuid under pressure and according to the vertical movement of said bolster relative to the side frame for conditioning the equipment for either light or heavy braking, and fluid pressure control communicationsV connecting said means and fluid pressure brake equipment, said communications extending through said header and longitudinally through said bolster to a point adjacent the pivotal support for thevehicle body and from thence to the iiuid pressure brake equipment.

14. In a vehicle emptyand load iiuid pressure brake equipment adapted to be automatically conditioned for either light or heavy braking, in

v combination, a vehicle on which the brake equipmentis mounted, a truck comprising a side frame and a truck bolster pivotally supporting said body and being movable vertically relative to the side frame according to the load on the body, a header secured to one end of the bolster, means secured to said header operative by fluid under pressure supplied to said fluid pressure brake equipment when the equipment is being charged With fluid under pressure and according tothe vertical movement of said bolster relative to the side frame rfor conditioning the equipment for either light or heavy braking, a headersecured to one Ysidejof saidy bolster adjacent the pivotal support for said body, and fluid pressure Ycontrol communications connecting said means and fluid pressure brake equipment, said communications extending through those on said header and longitudinally through said bolster and from the header secured to the side Yof the bolstercto the fluid pressure brake equipment. Y

ELLIS HEWITT. 

